MRI findings of rapidly progressive hepatocellular carcinoma

Prediction of macrotrabecular-massive hepatocellular carcinoma by using MR-based models and their prognostic implications

PURPOSE

To evaluate the efficacy of MRI-based radiomics and clinical models in predicting MTM-HCC. Additionally, to investigate the ability of the radiomics model designed for MTM-HCC identification in predicting disease-free survival (DFS) in patients with HCC.

METHODS

A total of 336 patients who underwent oncological resection for HCC between June 2007 and March 2021 were included. 127 patients in Cohort1 were used for MTM-HCC identification, and 209 patients in Cohort2 for prognostic analyses. Radiomics analysis was performed using volumes of interest of HCC delineated on pre-operative MRI images. Radiomics and clinical models were developed using Random Forest algorithm in Cohort1 and a radiomics probability (RP) of MTM-HCC was obtained from the radiomics model. Based on the RP, patients in Cohort2 were divided into a RAD-MTM-HCC (RAD-M) group and a RAD-non-MTM-HCC (RAD-nM) group. Univariate and multivariate Cox regression analyses were employed to identify the independent predictors for DFS of patients in Cohort2. Kaplan-Meier curves were used to compare the DFS between different groups pf patients based on the predictors.

RESULTS

The radiomics model for identifying MTM-HCC showed AUCs of 0.916 (95% CI: 0.858-0.960) and 0.833 (95% CI: 0.675-0.935), and the clinical model showed AUCs of 0.760 (95% CI: 0.669-0.836) and 0.704 (95% CI: 0.532-0.843) in the respective training and validation sets. Furthermore, the radiomics biomarker RP, portal or hepatic vein tumor thrombus, irregular rim-like arterial phase hyperenhancement (IRE) and AFP were independent predictors of DFS in patients with HCC. The DFS of RAD-nM group was significantly higher than that of the RAD-M group (p < .001).

CONCLUSION

MR-based clinical and radiomic models have the potential to accurately diagnose MTM-HCC. Moreover, the radiomics signature designed to identify MTM-HCC also can be used to predict prognosis in patients with HCC, realizing the diagnostic and prognostic aims at the same time.

Prediction of Non-Transplantable Recurrence After Liver Resection for Solitary Hepatocellular Carcinoma

Purpose

Using a combination model of preoperative imaging and clinical factors to predict non-transplantable recurrence (NTR) after liver resection and assist solitary hepatocellular carcinoma (HCC) patients in the selection of early treatment options.

Patients and Methods

A retrospective analysis was conducted on 253 solitary HCC patients who underwent radical resection and had preoperative MRI. NTR patients were defined as those exceeding the University of California, San Francisco (UCSF) criteria at the time of recurrence. Cox regression analysis was employed to identify preoperative factors associated with NTR based on clinical and tumor imaging characteristics. A risk scoring model (NTRScore) was developed and validated.

Results

Among the 253 patients, 86 (33.9%) experienced recurrence, and among those with recurrence, 34 patients (39.5%) developed NTR. In multivariate analysis, factors associated with NTR included alpha-fetoprotein (AFP) [>10 ng/mL] [HR: 3.42, 95% confidence interval (CI): 1.54-7.63, P: 0.003], arterial phase hyperenhancement (APHE) [HR: 2.23, 95% CI: 1.03-4.81, P: 0.041], washout[HR: 0.35, 95% CI: 0.15-0.84, P: 0.019], and capsule [HR: 0.44, 95% CI: 0.22-0.88, P: 0.021]. The β-coefficients of these variables were utilized to develop the weighted NTRScore(c-index 0.72, 95% CI: 0.65-0.79). The NTR occurrence increased across the three categories (low: 5.6%, medium: 13.6%, high: 35.1%, p < 0.001), and the Kaplan-Meier curves of recurrence-free survival(RFS) and overall survival(OS) show significant differences (p = 0.004 and p<0.001). Furthermore, the higher NTR categories may be associated with an increased risk of extrahepatic recurrence.

Conclusion

The NTRScore demonstrated strong discriminatory ability and may serve as a clinically useful tool to assist in risk stratification and potential to guide treatment and optimal surveillance for patients of solitary hepatocellular carcinoma within UCSF criteria.

Predicting Outcome after Percutaneous Ablation for Early-Stage Hepatocellular Carcinoma Using Various Imaging Modalities

Percutaneous ablation is a low-invasive, repeatable, and curative local treatment that is now recommended for early-stage hepatocellular carcinoma (HCC) that is not suitable for surgical resection. Poorly differentiated HCC has high-grade malignancy potential. Microvascular invasion is frequently seen, even in tumors smaller than 3 cm in diameter, and prognosis is poor after percutaneous ablation. Biopsy has a high risk of complications such as bleeding and dissemination; therefore, it has limitations in determining HCC tumor malignancy prior to treatment. Advances in diagnostic imaging have enabled non-invasive diagnosis of tumor malignancy. We describe the usefulness of ultrasonography, computed tomography, magnetic resonance imaging, and 18F-fluorodeoxyglucose positron emission tomography for predicting outcome after percutaneous ablation for HCC.

Estimating postsurgical outcomes of patients with a single hepatocellular carcinoma using gadoxetic acid-enhanced MRI: risk scoring system development and validation

OBJECTIVES

To develop and validate risk scoring systems using gadoxetic acid-enhanced liver MRI features and clinical factors that predict recurrence-free survival (RFS) of a single hepatocellular carcinoma (HCC).

METHODS

Consecutive 295 patients with treatment-naïve single HCC who underwent curative surgery were retrospectively enrolled from two centers. Cox proportional hazard models developed risk scoring systems whose discriminatory powers were validated using external data and compared to the Barcelona Clinic Liver Cancer (BCLC) or American Joint Committee on Cancer (AJCC) staging systems using Harrell's C-index.

RESULTS

Independent variables-tumor size (per cm; hazard ratio [HR], 1.07; 95% confidence interval [CI]: 1.02-1.13; p = 0.005), targetoid appearance (HR, 1.74; 95% CI: 1.07-2.83; p = 0.025), radiologic tumor in vein or tumor vascular invasion (HR, 2.59; 95% CI: 1.69-3.97; p < 0.001), the presence of a nonhypervascular hypointense nodule on the hepatobiliary phase (HR, 4.65; 95% CI: 3.03-7.14; p < 0.001), and pathologic macrovascular invasion (HR, 2.60; 95% CI: 1.51-4.48; p = 0.001)-with tumor markers (AFP ≥ 206 ng/mL or PIVKA-II ≥ 419 mAU/mL) derived pre- and postoperative risk scoring systems. The risk scores showed comparably good discriminatory powers in the validation set (C-index, 0.75-0.82) and outperformed the BCLC (C-index, 0.61) and AJCC staging systems (C-index, 0.58; ps < 0.05). The preoperative scoring system stratified the patients into low-, intermediate-, and high-risk for recurrence, whose 2-year recurrence rate was 3.3%, 31.8%, and 85.7%, respectively.

CONCLUSION

The developed and validated pre- and postoperative risk scoring systems can estimate RFS after surgery for a single HCC.

KEY POINTS

• The risk scoring systems predicted RFS better than the BCLC and AJCC staging systems (C-index, 0.75-0.82 vs. 0.58-0.61; ps < 0.05). • Five variables-tumor size, targetoid appearance, radiologic tumor in vein or vascular invasion, the presence of a nonhypervascular hypointense nodule on the hepatobiliary phase, and pathologic macrovascular invasion-combined with tumor markers derived risk scoring systems predicting postsurgical RFS for a single HCC. • In the risk scoring system using preoperatively-available factors, patients were classified into three distinct risk groups, with 2-year recurrence rates in the low-, intermediate-, and high-risk groups being 3.3%, 31.8%, and 85.7% in the validation set.

Radiologic features of hepatocellular carcinoma related to prognosis

The cross-sectional imaging findings play a crucial role in the diagnosis of hepatocellular carcinoma (HCC). Recent studies have shown that imaging findings of HCC are not only relevant for the diagnosis of HCC, but also for identifying genetic and pathologic characteristics and determining prognosis. Imaging findings such as rim arterial phase hyperenhancement, arterial phase peritumoral hyperenhancement, hepatobiliary phase peritumoral hypointensity, non-smooth tumor margin, low apparent diffusion coefficient, and the LR-M category of the Liver Imaging-Reporting and Data System have been reported to be associated with poor prognosis. In contrast, imaging findings such as enhancing capsule appearance, hepatobiliary phase hyperintensity, and fat in mass have been reported to be associated with a favorable prognosis. Most of these imaging findings were examined in retrospective, single-center studies that were not adequately validated. However, the imaging findings can be applied for deciding the treatment strategy for HCC, if their significance can be confirmed by a large multicenter study. In this literature, we would like to review imaging findings related to the prognosis of HCC as well as their associated clinicopathological characteristics.

Optimizing CT and MRI criteria for differentiating intrahepatic mass-forming cholangiocarcinoma and hepatocellular carcinoma

BACKGROUND

Accurate diagnosis of intrahepatic mass-forming cholangiocarcinoma (IMCC) is crucial with regard to the choice of patient management and treatment options.

PURPOSE

To evaluate the feasibility and diagnostic performance of the LI-RADS M (LR-M) targetoid criteria on computed tomography (CT) and gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) in differentiating IMCC from hepatocellular carcinoma (HCC).

MATERIAL AND METHODS

A total of 118 patients with IMCC and HCC were included who underwent CT and EOB-MRI examinations. Multivariate analysis was used to determine the strongest predictors differentiating IMCC from HCC. Using these predictors, a predictive model for differentiating IMCC from HCC was constructed and the performance of the model was confirmed using the receiver operating characteristic curve.

RESULTS

Multivariate analyses revealed rim-like arterial phase hyperenhancement (rim APHE) on CT and rim APHE, delayed central enhancement (DCE), and targetoid hepatobiliary phase (HBP) on MRI as independent variables significantly differentiating IMCC from HCC. The multivariate logistic regression model incorporating the three variables on EOB-MRI was constructed with an area under the curve (AUC) of 0.946, sensitivity of 87.80%, specificity of 92.21%, and accuracy of 94.60%. Per the DeLong test, the multivariate logistic regression model showed significantly higher AUC than rim APHE on CT (0.946 vs. 0.871; P = 0.008) and MRI (0.946 vs. 0.876; P = 0.003), whereas rim APHE on CT and MRI did not differ significantly (P = 0.809).

CONCLUSION

The multivariate logistic regression model based on rim APHE, DCE, and targetoid HBP on EOB-MRI can effectively distinguish IMCC from HCC and is superior to any other targetoid appearance criterion of LI-RADS on CT and EOB-MRI.

Comparing Survival Outcomes of Patients With LI-RADS-M Hepatocellular Carcinomas and Intrahepatic Cholangiocarcinomas

BACKGROUND

There is a sparsity of data evaluating outcomes of patients with Liver Imaging Reporting and Data System (LI-RADS) (LR)-M lesions.

PURPOSE

To compare overall survival (OS) and progression free survival (PFS) between hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA) meeting LR-M criteria and to evaluate factors associated with prognosis.

STUDY TYPE

Retrospective.

SUBJECTS

Patients at risk for HCC with at least one LR-M lesion with histologic diagnosis, from 8 academic centers, yielding 120 patients with 120 LR-M lesions (84 men [mean age 62 years] and 36 women [mean age 66 years]).

FIELD STRENGTH/SEQUENCE

A 1.5 and 3.0 T/3D T₁ -weighted gradient echo, T₂ -weighted fast spin-echo.

ASSESSMENT

The imaging categorization of each lesion as LR-M was made clinically by a single radiologist at each site and patient outcome measures were collected.

STATISTICAL TESTS

OS, PFS, and potential independent predictors were evaluated by Kaplan-Meier method, log-rank test, and Cox proportional hazard model. A P value of <0.05 was considered significant.

RESULTS

A total of 120 patients with 120 LR-M lesions were included; on histology 65 were HCC and 55 were iCCA. There was similar median OS for patients with LR-M HCC compared to patients with iCCA (738 days vs. 769 days, P = 0.576). There were no significant differences between patients with HCC and iCCA in terms of sex (47:18 vs. 37:18, P = 0.549), age (63.0 ± 8.4 vs. 63.4 ± 7.8, P = 0.847), etiology of liver disease (P = 0.202), presence of cirrhosis (100% vs. 100%, P = 1.000), tumor size (4.73 ± 3.28 vs. 4.75 ± 2.58, P = 0.980), method of lesion histologic diagnosis (P = 0.646), and proportion of patients who underwent locoregional therapy (60.0% vs. 38.2%, P = 0.100) or surgery (134.8 ± 165.5 vs. 142.5 ± 205.6, P = 0.913). Using multivariable analysis, nonsurgical compared to surgical management (HR, 4.58), larger tumor size (HR, 1.19), and higher MELD score (HR, 1.12) were independently associated with worse OS.

DATA CONCLUSION

There was similar OS in patients with LR-M HCC and LR-M iCCA, suggesting that LR-M imaging features may more closely reflect patient outcomes than histology.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 5.

A radiomics nomogram for predicting cytokeratin 19-positive hepatocellular carcinoma: a two-center study

Objectives

We aimed to construct and validate a radiomics-based nomogram model derived from gadoxetic acid-enhanced magnetic resonance (MR) images to predict cytokeratin (CK) 19-positive (+) hepatocellular carcinoma (HCC) and patients' prognosis.

Methods

A two-center and time-independent cohort of 311 patients were retrospectively enrolled (training cohort, n = 168; internal validation cohort, n = 72; external validation cohort, n = 71). A total of 2286 radiomic features were extracted from multisequence MR images with the uAI Research Portal (uRP), and a radiomic feature model was established. A combined model was established by incorporating the clinic-radiological features and the fusion radiomics signature using logistic regression analysis. Receiver operating characteristic curve (ROC) was used to evaluate the predictive efficacy of these models. Kaplan-Meier survival analysis was used to assess 1-year and 2-year progression-free survival (PFS) and overall survival (OS) in the cohort.

Results

By combining radiomic features extracted in DWI phase, arterial phase, venous and delay phase, the fusion radiomics signature achieved AUCs of 0.865, 0.824, and 0.781 in the training, internal, and external validation cohorts. The final combined clinic-radiological model showed higher AUC values in the three datasets compared with the fusion radiomics model. The nomogram based on the combined model showed satisfactory prediction performance in the training (C-index, 0.914), internal (C-index, 0.855), and external validation (C-index, 0.795) cohort. The 1-year and 2-year PFS and OS of the patients in the CK19+ group were 76% and 73%, and 78% and 68%, respectively. The 1-year and 2-year PFS and OS of the patients in the CK19-negative (-) group were 81% and 77%, and 80% and 74%, respectively. Kaplan-Meier survival analysis showed no significant differences in 1-year PFS and OS between the groups (P = 0.273 and 0.290), but it did show differences in 2-year PFS and OS between the groups (P = 0.032 and 0.040). Both PFS and OS were lower in CK19+ patients.

Conclusion

The combined model based on clinic-radiological radiomics features can be used for predicting CK19+ HCC noninvasively to assist in the development of personalized treatment.

Radiomic analysis based on multi-phase magnetic resonance imaging to predict preoperatively microvascular invasion in hepatocellular carcinoma

BACKGROUND

The prognosis of hepatocellular carcinoma (HCC) remains poor and relapse occurs in more than half of patients within 2 years after hepatectomy. In terms of recent studies, microvascular invasion (MVI) is one of the potential predictors of recurrence. Accurate preoperative prediction of MVI is potentially beneficial to the optimization of treatment planning.

AIM

To develop a radiomic analysis model based on pre-operative magnetic resonance imaging (MRI) data to predict MVI in HCC.

METHODS

A total of 113 patients recruited to this study have been diagnosed as having HCC with histological confirmation, among whom 73 were found to have MVI and 40 were not. All the patients received preoperative examination by Gd-enhanced MRI and then curative hepatectomy. We manually delineated the tumor lesion on the largest cross-sectional area of the tumor and the adjacent two images on MRI, namely, the regions of interest. Quantitative analyses included most discriminant factors (MDFs) developed using linear discriminant analysis algorithm and histogram analysis with MaZda software. Independent significant variables of clinical and radiological features and MDFs for the prediction of MVI were estimated and a discriminant model was established by univariate and multivariate logistic regression analysis. Prediction ability of the above-mentioned parameters or model was then evaluated by receiver operating characteristic (ROC) curve analysis. Five-fold cross-validation was also applied via R software.

RESULTS

The area under the ROC curve (AUC) of the MDF (0.77-0.85) outperformed that of histogram parameters (0.51-0.74). After multivariate analysis, MDF values of the arterial and portal venous phase, and peritumoral hypointensity in the hepatobiliary phase were identified to be independent predictors of MVI (P < 0.05). The AUC value of the model was 0.939 [95% confidence interval (CI): 0.893-0.984, standard error: 0.023]. The result of internal five-fold cross-validation (AUC: 0.912, 95%CI: 0.841-0.959, standard error: 0.0298) also showed favorable predictive efficacy.

CONCLUSION

Noninvasive MRI radiomic model based on MDF values and imaging biomarkers may be useful to make preoperative prediction of MVI in patients with primary HCC.

Clinical features and diagnostic and therapeutic strategies of hepatic dysplastic nodules

Hepatic dysplastic nodules (DNs) are a group of neoplastic lesions with a diameter of more than 1 cm that belong to precancerous lesions, with abnormal cytoplasm and cells but without malignant basis in histology. Hepatic DNs lack typical tumor markers and clinical symptoms, and their clinical diagnosis relys mainly on imaging or/and tissue pathological examination. Thanks to the further research on the pathogenesis of hepatic DNs and the development of imaging technology, the combination of medical history, various examinationss, individual tumor markers, and imaging and histopathology techniques can significantly improve the early detection and diagnosis accuracy for hepatic DNs, and reduce the rate of missed and false diagnosis. Due to the potential malignancy risk of hepatic DNs, intervention measures should be carried out on hepatic DNs at all stages, in order to block the transformation process of DNs into hepatocellular carcinoma (HCC), which is of great clinical significance to reduce the incidence and mortality of HCC.

[Radiologic Diagnosis of Hepatocellular Carcinoma]

There are various causes of hepatocellular carcinoma, including viral hepatitis, and treatment strategies are often established based on the radiology diagnosis, unlike other carcinomas. The liver imaging reporting and data system (LI-RADS) is a diagnostic system developed by the American College of Radiologists for clear communication and standardized reports of the liver imaging findings. It was recently included in the clinical guidance of the American Association for the Study of Liver Diseases. In addition, the radiologic findings of hepatocellular carcinoma (HCC) enable a prediction of the prognosis after treatment and a diagnosis of diseases because the use of gadoxetic acid MRI has become more common. Thus, the role of radiology for the diagnosis and treatment of HCC is expected to be developed further.

Pathologic, Molecular, and Prognostic Radiologic Features of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a malignancy with variable biologic aggressiveness based on the tumor grade, presence or absence of vascular invasion, and pathologic and molecular classification. Knowledge and understanding of the prognostic implications of different pathologic and molecular phenotypes of HCC are emerging, with therapeutics that promise to provide improved outcomes in what otherwise remains a lethal cancer. Imaging has a central role in diagnosis of HCC. However, to date, the imaging algorithms do not incorporate prognostic features or subclassification of HCC according to its biologic aggressiveness. Emerging data suggest that some imaging features and further radiologic, pathologic, or radiologic-molecular phenotypes may allow prediction of the prognosis of patients with HCC. An invited commentary by Bashir is available online. Online supplemental material is available for this article. ^©RSNA, 2021.

Prognosis after Curative Resection of Single Hepatocellular Carcinoma with A Focus on LI-RADS Targetoid Appearance on Preoperative Gadoxetic Acid-Enhanced MRI

Objective

To evaluate the prognostic implications of preoperative magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) with a focus on those with targetoid appearance based on the Liver Imaging Reporting and Data System (LI-RADS), as well as known microvascular invasion (MVI) features.

Materials and Methods

This retrospective study included 242 patients (190 male; mean age, 57.1 years) who underwent surgical resection of a single HCC (≤ 5 cm) as well as preoperative gadoxetic acid-enhanced MRI between January 2012 and March 2015. LI-RADS category was assigned, and the LR-M category was further classified into two groups according to rim arterial-phase hyperenhancement (APHE). The imaging features associated with MVI were also assessed. The overall survival (OS), recurrence-free survival (RFS), and their associated factors were evaluated.

Results

Among the 242 HCCs, 190 (78.5%), 25 (10.3%), and 27 (11.2%) were classified as LR-4/5, LR-M with rim APHE, and LR-M without rim APHE, respectively. LR-M with rim APHE (vs. LR-4/5; hazard ratio [HR] for OS, 5.48 [p = 0.002]; HR for RFS, 2.09 [p = 0.042]) and tumor size (per cm increase; HR for OS, 6.04 [p = 0.009]; HR for RFS, 1.77 [p = 0.014]) but not MVI imaging features (p > 0.05) were independent factors associated with OS and RFS. Compared to the 5-year OS and RFS rates in the LR-4/5 group (93.9% and 66.8%, respectively), the LR-M with rim APHE group had significantly lower rates (68.0% and 45.8%, respectively, both p < 0.05), while the LR-M without rim APHE group did not significantly differ in the survival rates (91.3% and 80.2%, respectively, both p > 0.05).

Conclusion

Further classification of LR-M according to the presence of rim APHE may help predict the postoperative prognosis of patients with a single HCC.

Nomogram development and validation to predict hepatocellular carcinoma tumor behavior by preoperative gadoxetic acid-enhanced MRI

OBJECTIVES

Pretreatment evaluation of tumor biology and microenvironment is important to predict prognosis and plan treatment. We aimed to develop nomograms based on gadoxetic acid-enhanced MRI to predict microvascular invasion (MVI), tumor differentiation, and immunoscore.

METHODS

This retrospective study included 273 patients with HCC who underwent preoperative gadoxetic acid-enhanced MRI. Patients were assigned to two groups: training (N = 191) and validation (N = 82). Univariable and multivariable logistic regression analyses were performed to investigate clinical variables and MRI features' associations with MVI, tumor differentiation, and immunoscore. Nomograms were developed based on features associated with these three histopathological features in the training cohort, then validated, and evaluated.

RESULTS

Predictors of MVI included tumor size, rim enhancement, capsule, percent decrease in T1 images (T1_D%), standard deviation of apparent diffusion coefficient, and alanine aminotransferase levels, while capsule, peritumoral enhancement, mean relaxation time on the hepatobiliary phase (T1_E), and alpha-fetoprotein levels predicted tumor differentiation. Predictors of immunoscore included the radiologic score constructed by tumor number, intratumoral vessel, margin, capsule, rim enhancement, T1_D%, relaxation time on plain scan (T1_P), and alpha-fetoprotein and alanine aminotransferase levels. Three nomograms achieved good concordance indexes in predicting MVI (0.754, 0.746), tumor differentiation (0.758, 0.699), and immunoscore (0.737, 0.726) in the training and validation cohorts, respectively.

CONCLUSION

MRI-based nomograms effectively predict tumor behaviors in HCC and may assist clinicians in prognosis prediction and pretreatment decisions.

KEY POINTS

• This study developed and validated three nomograms based on gadoxetic acid-enhanced MRI to predict MVI, tumor differentiation, and immunoscore in patients with HCC. • The pretreatment prediction of tumor microenvironment may be useful to guide accurate prognosis and planning of surgical and immunological therapies for individual patients with HCC.

Liver Imaging Reporting and Data System Category on Magnetic Resonance Imaging Predicts Recurrence of Hepatocellular Carcinoma After Liver Transplantation Within the Milan Criteria: A Multicenter Study

BACKGROUND

This study was designed to investigate the association between Liver Imaging Reporting and Data System (LI-RADS) category and recurrence of hepatocellular carcinoma (HCC) after primary liver transplantation (LT) within the Milan criteria.

METHODS

This multicenter, retrospective study included 140 recipients who underwent living donor LT (LDLT) for treatment-naïve HCC and pretransplant contrast-enhanced magnetic resonance imaging (MRI) between 2009 and 2013. LI-RADS categories were assigned using LI-RADS version 2018. Recurrence-free survival (RFS) and associated factors were evaluated using Cox proportional hazards regression analysis, Kaplan-Meier analysis, and log-rank test. Histological grading and microvascular invasion (MVI) were analyzed on the pathologic examinations of explanted livers.

RESULTS

The overall 1-, 3-, 5-, and 7-year RFS rates were 95.6%, 92.6%, 90.2%, and 89.3%, respectively. In the multivariable analysis, independent predictors of recurrence included HCCs categorized as LR-M (hazard ratio [HR], 18.68; 95% confidence interval [CI], 5.79-60.23; P < 0.001) and the largest tumor size of ≥ 3 cm on MRI (HR, 4.18; 95% CI, 1.42-12.37; P = 0.010). The 5-year RFS rate was significantly lower in patients with HCCs categorized as LR-M than in those with HCCs categorized as LR-5 or 4 (LR-5/4) (36.9% vs. 95.8%, respectively; P < 0.001). HCCs categorized as LR-M exhibited significantly more MVI than HCCs categorized as LR-5/4 (57.1% vs. 17.5%, respectively; P = 0.002).

CONCLUSIONS

Patients with HCCs categorized as LR-M using LI-RADS version 2018 may have a worse prognosis after primary LT within the Milan criteria than those with HCCs categorized as LR-5/4.

Pre-radiofrequency ablation MRI imaging features predict the local tumor progression in hepatocellular carcinoma

To investigate whether MRI features could preoperatively predict local tumor progression (LTP) in patients with hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA) as the first-line treatment and improve a novel predictive model through developing a nomogram including various conventional MRI parameters. 105 patients with HCCs who had received RFA were enrolled. All patients had undergone conventional MRI before RFA. Uni- and multivariable analyses for LTP were assessing using a Cox proportional hazards model. The developed MRI-based nomogram was further designed based on multivariable logistic analysis in our study and the usefulness of the developed model was validated according to calibration curves and the C-index. Rim enhancement (hazard ratio: 2.689, P = .044) and the apparent diffusion coefficient (ADC) values (hazard ratio: 0.055, P = .038) were statistically significant independent predictors of LTP after RFA at multivariable analysis. The performance of the nomogram incorporating two MRI parameters (with a C-index of 0.782) was improved compared with that based on rim enhancement and ADC alone (with C-index values of 0.630 and 0.728, respectively). The calibration curve of the MRI-based nomogram showed good conformance between evaluation and observation at 0.5, 1, and 1.5 years after RFA. The preliminary predictive model based on MRI findings including rim enhancement and ADC value could be used preoperatively to estimate the risk of LTP of HCC after RFA as the first-line treatment.

Prognostic value of LI-RADS category on gadoxetic acid-enhanced MRI and 18F-FDG PET-CT in patients with primary liver carcinomas

OBJECTIVES

To evaluate the postoperative prognostic value of the Liver Imaging Reporting and Data System (LI-RADS) category on gadoxetic acid-enhanced MRI and 18F-fluorodeoxyglucose PET-CT in patients with primary liver carcinomas (PLCs).

METHODS

A total of 189 patients with chronic liver disease and surgically proven single PLC (42 intrahepatic cholangiocarcinomas and 21 combined hepatocellular-cholangiocarcinomas and 126 hepatocellular carcinomas [2:1 matching to non-HCC malignancies]) were retrospectively evaluated with gadoxetic acid-enhanced MRI and PET-CT. Two independent reviewers assigned an LI-RADS category for each observation. The tumor-to-liver standardized uptake value ratio (TLR) was calculated. The overall survival (OS), recurrence-free survival (RFS), and the associated factors were evaluated.

RESULTS

In multivariable analysis, LI-RADS category (LR-4 or LR-5 [LR-4/5] vs. LR-M; OS, hazard ratio [HR] 2.24, p = 0.006; RFS, HR 1.61, p = 0.028) and TLR (low, < 2.3 vs. high, ≥ 2.3; OS, HR 2.09, p = 0.014; RFS, HR 2.17, p < 0.001) were the independent factors for OS and RFS. For the LR-M group, the high TLR group showed lower OS and RFS rates than the low TLR group (OS, p = 0.008; RFS, p < 0.001). For the LR-4/5 group, the OS and RFS rates were not significantly different between the high TLR and low TLR groups (both p > 0.05).

CONCLUSIONS

Both LI-RADS category on MRI and TLR on PET-CT are associated with the postoperative prognosis of PLCs. The prognosis of PLCs classified as LR-M can be further stratified according to the TLR group, but not for the PLCs classified as LR-4/5.

KEY POINTS

• The LI-RADS category (LR-4/5 vs. LR-M) and tumor-to-liver standardized uptake value ratio (TLR, low vs. high) were independent factors for postoperative prognosis of primary liver carcinomas (PLCs). • For PLCs classified as LR-M, the TLR group helps stratify the postoperative prognosis of PLCs, with the high TLR group having a poor prognosis and the low TLR group having a better prognosis (p = 0.008 for OS and p < 0.001 for RFS). • For PLCs classified as LR-4/5, the OS and RFS rates were not significantly different between the high TLR and low TLR groups (both p > 0.05).

Retrospective CT/MRI Texture Analysis of Rapidly Progressive Hepatocellular Carcinoma

Rapidly progressive hepatocellular carcinoma (RPHCC) is a subset of hepatocellular carcinoma that demonstrates accelerated growth, and the radiographic features of RPHCC versus non-RPHCC have not been determined. The purpose of this retrospective study was to use baseline radiologic features and texture analysis for the accurate detection of RPHCC and subsequent improvement of clinical outcomes. We conducted a qualitative visual analysis and texture analysis, which selectively extracted and enhanced imaging features of different sizes and intensity variation including mean gray-level intensity (mean), standard deviation (SD), entropy, mean of the positive pixels (MPP), skewness, and kurtosis at each spatial scaling factor (SSF) value of RPHCC and non-RPHCC tumors in a computed tomography (CT) cohort of n = 11 RPHCC and n = 11 non-RPHCC and a magnetic resonance imaging (MRI) cohort of n = 13 RPHCC and n = 10 non-RPHCC. There was a statistically significant difference across visual CT irregular margins p = 0.030 and CT texture features in SSF between RPHCC and non-RPHCC for SSF-6, coarse-texture scale, mean p = 0.023, SD p = 0.053, MPP p = 0.023. A composite score of mean SSF-6 binarized + SD SSF-6 binarized + MPP SSF-6 binarized + irregular margins was significantly different between RPHCC and non-RPHCC (p = 0.001). A composite score ≥3 identified RPHCC with a sensitivity of 81.8% and specificity of 81.8% (AUC = 0.884, p = 0.002). CT coarse-texture-scale features in combination with visually detected irregular margins were able to statistically differentiate between RPHCC and non-RPHCC. By developing an image-based, non-invasive diagnostic criterion, we created a composite score that can identify RPHCC patients at their early stages when they are still eligible for transplantation, improving the clinical course of patient care.

Prediction of prognostic risk factors in hepatocellular carcinoma with transarterial chemoembolization using multi-modal multi-task deep learning

BACKGROUND

Due to heterogeneity of hepatocellular carcinoma (HCC), outcome assessment of HCC with transarterial chemoembolization (TACE) is challenging.

METHODS

We built histologic-related scores to determine microvascular invasion (MVI) and Edmondson-Steiner grade by training CT radiomics features using machine learning classifiers in a cohort of 494 HCCs with hepatic resection. Meanwhile, we developed a deep learning (DL)-score for disease-specific survival by training CT imaging using DL networks in a cohort of 243 HCCs with TACE. Then, three newly built imaging hallmarks with clinicoradiologic factors were analyzed with a Cox-Proportional Hazard (Cox-PH) model.

FINDINGS

In HCCs with hepatic resection, two imaging hallmarks resulted in areas under the curve (AUCs) of 0.79 (95% confidence interval [CI]: 0.71-0.85) and 0.72 (95% CI: 0.64-0.79) for predicting MVI and Edmondson-Steiner grade, respectively, using test data. In HCCs with TACE, higher DL-score (hazard ratio [HR]: 3.01; 95% CI: 2.02-4.50), American Joint Committee on Cancer (AJCC) stage III+IV (HR: 1.71; 95% CI: 1.12-2.61), Response Evaluation Criteria in Solid Tumors (RECIST) with stable disease + progressive disease (HR: 2.72; 95% CI: 1.84-4.01), and TACE-course > 3 (HR: 0.65; 95% CI: 0.45-0.76) were independent prognostic factors. Using these factors via a Cox-PH model resulted in a concordance index of 0.73 (95% CI: 0.71-0.76) for predicting overall survival and AUCs of 0.85 (95% CI: 0.81-0.89), 0.90 (95% CI: 0.86-0.94), and 0.89 (95% CI: 0.84-0.92), respectively, for predicting 3-year, 5-year, and 10-year survival.

INTERPRETATION

Our study offers a DL-based, noninvasive imaging hallmark to predict outcome of HCCs with TACE.

FUNDING

This work was supported by the key research and development program of Jiangsu Province (Grant number: BE2017756).

Addressing cultural diversity: the hepatitis B clinical specialist perspective

Objectives: Hepatitis B is a viral infection primarily affecting people from culturally diverse communities in Australia. While vaccination prevents infection, there is increasing mortality resulting from liver damage associated with chronic infection. Deficits in the national policy and clinical response to hepatitis B result in a low diagnosis rate, inadequate testing and diagnosis processes, and poor access to hepatitis B treatment services. While research identifies inadequate hepatitis B knowledge among people with the virus and primary health care workers, this project sought to identify how specialist clinicians in Australia negotiate cultural diversity, and provide often complex clinical information to people with hepatitis B. Design: A vignette was developed and presented to thirteen viral hepatitis specialist clinicians prior to an electronically recorded interview. Recruitment continued until saturation of themes was reached. Data were thematically coded into themes outlined in the interview schedule. Ethical approval for the research was provided by the La Trobe University Human Research Ethics Committee. Results: Key messages provided to patients with hepatitis B by clinical specialists were identified. These messages were not consistently provided to all patients with hepatitis B, but were determined on perceptions of patient knowledge, age and highest educational level. While the vignette stated that English was not an issue for the patient, most specialists identified the need for an interpreter. Combating stigma related to hepatitis B was seen as important by the specialists and this was done through normalising the virus. Having an awareness of different cultural understandings about hepatitis B specifically, and health and well-being generally, was noted as a communication strategy. Conclusion: Key core competencies need to be developed to deliver educational messages to people with hepatitis B within clinical encounters. The provision of adequate resources to specialist clinics will assist in addressing gaps in the clinical response to hepatitis B.

Texture Analysis Based on Preoperative Magnetic Resonance Imaging (MRI) and Conventional MRI Features for Predicting the Early Recurrence of Single Hepatocellular Carcinoma after Hepatectomy

RATIONALE AND OBJECTIVES

To investigate the value of texture analysis and conventional magnetic resonance imaging (MRI) features for predicting the early recurrence (ER) of single hepatocellular carcinoma (HCC) after hepatectomy.

MATERIALS AND METHODS

A total of 100 HCC patients were first divided into group A (tumor diameter ≤3 cm) and group B (tumor diameter >3 cm) and then classified into two subgroups with ER or nonearly recurrence. Textural parameters (skewness, kurtosis, uniformity, energy, entropy, and correlation) based on MR images and conventional MRI features were compared between the ER and nonearly recurrence subgroups. Predictive factors for ER were further assessed with multivariate logistic regression analysis. Receiver operating characteristic curve was performed to assess the predictive power.

RESULTS

There were 53 patients in group A and 47 patients in group B. On arterial phase analysis, tumors with ER displayed significantly lower uniformity and higher entropy in group A, and higher skewness and entropy in group B. On portal venous phase analysis, tumors with ER had significantly lower kurtosis and energy in group A, and higher entropy in group B. Irregular margin in groups A and B, and arterial peritumoral enhancement and capsule presence in group B were associated with ER. In multivariate logistic regression analysis, uniformity and entropy based on arterial phase images and irregular margin in group A, and skewness and entropy based on arterial phase images and arterial peritumoral enhancement in group B were independent predictors for ER. Entropy displayed higher predictive power for ER.

CONCLUSION

Texture analysis based on preoperative MRI are potential quantitative predictors of ER in HCC patients after hepatectomy, and may provide more information for preoperative treatment decision-making and follow up.

Magnetic resonance texture analysis for the identification of cytokeratin 19-positive hepatocellular carcinoma

PURPOSE

To investigate potential findings associated with cytokeratin 19 (CK19)-positive HCC, with special emphasis on MR texture analysis.

MATERIALS AND METHODS

Forty-eight patients with CK19-negative HCC and 38 patients with CK19-positive were retrospectively evaluated by texture analysis based on conventional MRI. Clinicalpathological characteristics, conventional MR imaging findings, and the MR texture analysis contained of 2415 texture features in the seven conventional sequences were compared. Significant features for differentiating were identified by univariate and multivariate analyses. Receiver operating characteristic analyses of the significant findings were performed and compared to evaluate their diagnostic performance.

RESULTS

There was no significant difference between the top1 texture feature (three-dimensional standard deviation separation of intensity on T2-weighted original images, abbreviated as: StdSeparation 3D) and the combined top1-6 feature in identifying CK19-positive HCC(P = 0.660). Univariate and multivariate analyses indicated that serum alpha-fetoprotein (AFP) level ≥400 ng/mL(P = 0.013), arterial rim enhancement(P = 0.005), and StdSeparation 3D texture character(P = 0.002) were independent variables associated with CK19-positive HCCs. The combination of the three indices showed a better performance than AFP level(P = 0.0028), arterial rim enhancement(P < 0.0001), and their combination(P = 0.0098); while no significantly better than the StdSeparation 3D texture character alone(P = 0.0788). An acceptable discrimination(AUC = 0.765) with both sensitivity and specificity greater than 75% was achieved for StdSeparation 3D texture character.

CONCLUSION

Serum AFP level ≥400 ng/mL, arterial rim enhancement, and the StdSeparation 3D texture character were independently associated with CK19-positive HCC. The StdSeparation 3D texture character may be a reliable imaging biomarker which can improve the diagnostic performance.

Small hepatocellular carcinoma: using MRI to predict histological grade and Ki-67 expression

AIMS

To investigate the predictive indicators of small aggressive hepatocellular carcinomas by examining the association between preoperative magnetic resonance imaging (MRI) parameters and Ki-67 expression and histological grade.

MATERIALS AND METHODS

Sixty patients with small hepatocellular carcinomas (tumour diameter: ≤3 cm, tumour numbers: ≤2) who underwent curative resection or biopsy after contrast-enhanced and diffusion-weighted MRI were evaluated retrospectively. Signal intensity (SI) of the whole lesion and erector spinae muscle was measured quantitatively. Tumour-to-muscle SI ratio was calculated. The association between these MRI parameters and histological grade and Ki-67 level was then investigated.

RESULTS

There was a significant correlation between tumour-to-muscle SI ratio and histological grade in tissues captured during the non-enhanced T1-weighted (p=0.001), arterial phase (p=0.001), and portal venous phase (p=0.036) of dynamic contrast-enhanced MRI and apparent diffusion coefficient (p=0.027). Arterial inhomogeneous enhancement was also correlated with high-Ki-67 expression (p=0.032).

CONCLUSIONS

Preoperative MRI may serve as a non-invasive tool for prediction of small, aggressive hepatocellular carcinomas, which may otherwise be treated conservatively.

Current status of imaging biomarkers predicting the biological nature of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is heterogeneous in terms of its biological nature. Various factors related to its biological nature, including size, multifocality, macroscopic morphology, grade of differentiation, macro/microvascular invasion, bile duct invasion, intra-tumoral fat and molecular factors, and their value as prognostic imaging biomarkers have been reported. And recently, genome-based molecular HCC classification correlated with clinical outcome has been elucidated. The imaging biomarkers suggesting a less aggressive nature of HCC are smaller size, solitary tumor, smooth margin suggesting small nodular type with indistinct margin and simple nodular type with distinct margin, capsule, imaging biomarkers predicting early or well-differentiated grade, intra-tumoral fat detection, and low fluorodeoxyglucose (FDG) accumulation. The imaging biomarkers suggesting an aggressive HCC nature are larger size, multifocality, non-smooth margin suggesting simple nodular type with extranodular growth, confluent multinodular, and infiltrative type, imaging biomarkers predicting poor differentiation, macrovascular tumor thrombus, predicting microvascular invasion imaging biomarkers, bile duct dilatation or tumor thrombus, and high FDG accumulation. In the genome-based molecular classification, CTNNB-1 mutated HCC shows a less aggressive nature, while CK19/EpCAM positive HCC and macrotrabecular massive HCC show an aggressive one. Better understanding of these imaging biomarkers can contribute to devising more appropriate treatment plans for HCC.

Hepatocellular Carcinoma with Irregular Rim-Like Arterial Phase Hyperenhancement: More Aggressive Pathologic Features

BACKGROUND AND AIMS

The purpose of our study was to examine the histopathologic characteristics of hepatocellular carcinoma (HCC) with irregular rim-like arterial phase enhancement (IRE), which has been reported to be associated with more aggressive tumor behavior.

METHODS

We investigated 84 pathologically confirmed HCCs in 84 patients who underwent curative hepatic resection after gadoxetate-enhanced magnetic resonance imaging between January 2008 and February 2013. Two abdominal radiologists independently reviewed these images and classified HCCs into two categories: HCC showing IRE (IRE-HCC) and HCC showing hypoenhancement or diffuse arterial enhancement (non-IRE-HCC). Twenty-two HCCs were classified as IRE-HCCs, and 51 were classified as non-IRE-HCCs concordantly by both reviewers. The remaining 11 HCCs, on whose radiologic classifications the reviewers disagreed, were classified as HCCs with intermediate enhancement patterns. The HCC clinicopathologic characteristics and patient outcomes were then compared.

RESULTS

IRE-HCCs showed more frequent microvascular invasion (91 vs. 35%), lower microvascular density (246.5 vs. 426.5/mm²), higher proportions of sinusoid-like microvascular pattern (55 vs. 0%) and macrotrabecular pattern (45 vs. 0%), and larger areas of tumor necrosis (15 vs. 0%) and fibrous stroma (8.3 vs. 2.1%) than non-IRE-HCCs. IRE-HCCs also expressed higher levels of immunomarkers of hypoxia (carbonic anhydrase IX, 64 vs. 8%) and stemness (EpCAM, 50 vs. 20%). p values were < 0.001 for all comparisons except for EpCAM (p = 0.026). HCCs with intermediate enhancement patterns showed mixed/intermediate pathologic features from both IRE- and non-IRE-HCCs. IRE-HCC patients showed poorer 5-year disease-free survival after curative resection than non-IRE-HCC patients (p = 0.005).

CONCLUSIONS

IRE-HCCs demonstrate aggressive histopathologic features, including more hypoxic and fibrotic tumor microenvironments and increased stemness, compared to non-IRE-HCCs. IRE might therefore serve as a noninvasive imaging biomarker for aggressive HCC.

Imaging features related with prognosis of hepatocellular carcinoma

We discuss various imaging features that have been reported to be associated with the prognosis of hepatocellular carcinoma (HCC) but not included in the current staging systems: findings related with microvascular invasion, tumor encapsulation, intratumoral fat, presence of satellite nodules, peritumoral hypointensity on hepatobiliary phase images of gadoxetic-acid enhanced MRI, restricted diffusion, and irregular rim-like hyperenhancement. Current evidence suggests that larger (> 2 cm) tumor size, presence of satellite nodules, presence of irregular rim-like hyperenhancement of a tumor, peritumoral parenchymal enhancement in the arterial phase, and peritumoral hypointensity observed on hepatobiliary phase images are independent imaging features to portend a worse prognosis in patients with hepatocellular carcinoma.

Imaging Features of Gadoxetic Acid-enhanced and Diffusion-weighted MR Imaging for Identifying Cytokeratin 19-positive Hepatocellular Carcinoma: A Retrospective Observational Study

Purpose To determine the preoperative magnetic resonance (MR) imaging findings potentially most useful for predicting cytokeratin 19 (CK19)-positive hepatocellular carcinoma (HCC) and to evaluate the prognosis after curative resection in patients with a single HCC lesion positive for CK19 compared with patients with HCC who are negative for CK19. Materials and Methods The institutional review board approved this study and waived the requirement for informed consent. Two hundred four patients with CK19-negative HCC and 38 with CK19-positive HCC who underwent curative resection after gadoxetic acid-enhanced and diffusion-weighted MR imaging were retrospectively evaluated in a single institution. Two radiologists evaluated preoperative findings at MR imaging. Significant findings for differentiating the two groups were identified at univariate and multivariate analyses. By using receiver operating characteristic analysis, the optimal cut-off values for quantitative variables were determined. Recurrence-free survival rates after surgery were also compared between groups. Results At multivariate analysis, irregular tumor margin (P = .024), arterial rim enhancement (P < .001), lower tumor-to-liver signal intensity (SI) ratio on hepatobiliary phase (HBP) images (≤0.522; P = .01), and lower tumor-to-liver apparent diffusion coefficient (ADC) ratio (≤0.820; P < .001) were independent significant factors to predict CK19-positive HCC. When three of these four criteria were combined, 63.2% (24 of 38; 95% confidence interval: 46.0%, 78.2%) of CK19-positive HCCs were identified with a specificity of 90.7% (185 of 204; 95% confidence interval: 46.0%, 78.2%). When all four criteria were satisfied, specificity was 99.5% (203 of 204; 95% confidence interval: 97.3%, 100%). Recurrence-free survival rates were significantly lower in patients with CK19-positive HCCs compared with those with CK19-negative HCCs after curative resection (63.9% vs 90.0% at 1 year, 63.9% vs 79.9% at 2 years, and 54.8% vs 70.2% at 3 years, P = .001 by log-rank test). Conclusion At gadoxetic acid-enhanced and diffusion-weighted MR imaging, irregular margin, arterial phase rim enhancement, lower tumor-to-liver ADC ratio, and lower tumor-to-liver SI ratio at HBP imaging may be helpful to predict CK19-positive HCC with early recurrence (<2 years) after curative resection. ^© RSNA, 2017 Online supplemental material is available for this article.

Preoperative gadoxetic acid-enhanced MRI for predicting microvascular invasion in patients with single hepatocellular carcinoma

BACKGROUND & AIMS

This study aimed to identify preoperative magnetic resonance (MR) imaging biomarkers for predicting microvascular invasion (MVI), to determine their diagnostic performance and to evaluate whether they are associated with early recurrence after surgery for single hepatocellular carcinoma (HCC).

METHODS

The study included 197 patients with surgically resected HCC (≤5cm) who underwent preoperative gadoxetic acid-enhanced MR imaging. Significant MR imaging findings for predicting MVI were identified by univariate and multivariate analyses. Early recurrence rates (<2years) were analyzed with respect to significant imaging findings for predicting MVI.

RESULTS

Three MR imaging features were independently associated with MVI: arterial peritumoral enhancement (odds ratio [OR]=5.184; 95% confidence interval [CI]: 2.228, 12.063; p<0.001), non-smooth tumor margin (OR=3.555; 95% CI: 1.627, 7.769; p=0.001), and peritumoral hypointensity on hepatobiliary phase (HBP) (OR=4.705; 95% CI: 1.671, 13.246; p=0.003). When two of three findings were combined, the specificity was 92.5% (124/134). When all three findings were satisfied, the specificity was 99.3% (133/134). Early recurrence rates were significantly higher in patients with single HCC, with two or three significant MR imaging findings, compared to those with none (27.9% vs. 12.6%, respectively, p=0.030).

CONCLUSIONS

A combination of two or more of the following; arterial peritumoral enhancement, non-smooth tumor margin, and peritumoral hypointensity on HBP, can be used as a preoperative imaging biomarker for predicting MVI, with specificity >90%, and is associated with early recurrence after surgery of single HCC. Lay summary: A combination of two or more of the following; arterial peritumoral enhancement, non-smooth tumor margin, and peritumoral hypointensity on hepatobiliary phase, can be used as a preoperative imaging biomarker for predicting microvascular invasion, with specificity >90%, and is associated with early recurrence after curative resection of single HCC.

Magnetic resonance imaging of the cirrhotic liver: diagnosis of hepatocellular carcinoma and evaluation of response to treatment - Part 2

In the second part of this review, we will describe the ancillary imaging features of hepatocellular carcinoma (HCC) that can be seen on standard magnetic resonance imaging (MRI) protocol, and on novel and emerging protocols such as diffusion weighted imaging and utilization of hepatocyte-specific/hepatobiliary contrast agent. We will also describe the morphologic sub-types of HCC, and give a simplified non-invasive diagnostic algorithm for HCC, followed by a brief description of the liver imaging reporting and data system (LI-RADS), and MRI assessment of tumor response following locoregional therapy.

Bone Metastases of Hepatocellular Carcinoma: Appearance on MRI Using a Standard Abdominal Protocol

OBJECTIVE

The purpose of this study is to describe the MRI features of hepatocellular carcinoma (HCC) bone metastases.

MATERIALS AND METHODS

Thirty-three consecutive patients were included. Two radiologists performed qualitative and quantitative analysis. The coordinator searched for clinical and epidemiologic features related to patients and their primary liver tumors. Earlier MRI studies were also reviewed to determine whether bone metastases were already present and prospectively identified. Descriptive statistics and the Lin concordance correlation coefficient were used.

RESULTS

Chronic hepatitis C virus infection was the most common cause of liver disease (20/32; 62.5%), and diffuse and multifocal HCC were the most frequent types of liver HCCs (28/33; 84.8%). Most lesions were located at the spine (109/155; 70.3%), with high signal intensity on fat-suppressed T1-weighted (54/62; 87.1%) and T2-weighted (53/62; 85.5%) images. Bone metastases were predominantly nodular (48/62; 77.4%), confined to the vertebral body (40/60; 66.7%), and best visualized at the arterial phase (40/62; 64.5%). The ring pattern of enhancement was present in 23 of 62 lesions, and the remaining lesions showed diffuse enhancement. Thirty-five of 62 (56.4%) bone metastases showed arterial peak of enhancement. In 13 of 33 (39.9%) patients, bone metastases were not prospectively reported.

CONCLUSION

Most patients with bone metastases had chronic hepatitis C virus infection and diffuse or multifocal HCC. Metastases are most commonly appreciated as hypervascular focal moderately intensely enhancing nodular masses on the hepatic arterial dominant phase images, with concomitant moderately high signal intensity on fat-suppressed T1- and T2-weighted images.

Prognostic role of magnetic resonance imaging vs. computed tomography for hepatocellular carcinoma undergoing chemoembolization

BACKGROUND & AIMS

Computed tomography (CT) and magnetic resonance imaging (MRI) play important roles in diagnosis and staging of hepatocellular carcinoma (HCC). However, prognostic roles of radiological characteristics are not yet determined.

METHODS

Eighty-eight patients treated with chemoembolization were analysed. Radiological parameters at baseline were assessed in all patients using both dynamic CT and MRI. Treatment responses were assessed using modified RECIST 4 weeks after the first chemoembolization.

RESULTS

Gross vascular invasion (GVI), bile duct invasion, irregular tumour margin (ITM), peripheral ragged enhancement (PRE) and satellite nodules on CT or MRI were associated with non-response (stable disease or progression) after chemoembolization respectively (all P ≤ 0.05). GVI, ITM and PRE on CT or MRI were also independently associated with poor overall survival (OS) respectively (all P ≤ 0.05). Using these results, a prognostic scoring system for CT and MRI were developed; 0, absence of all three features (GVI, ITM and PRE); 1, presence of one feature; 2, presence of two features; and 3, presence of three features. After adjusting tumour size, tumour number and alpha-foetoprotein level, both CT and MRI scores were independently associated with OS (both P < 0.001). Patients with CT or MRI score ≥2 had a worse OS than those with score <2 (adjusted hazard ratios, 3.837 and 2.938 respectively). MRI-specific parameters such as signal intensity on T2- or T1-weighted images, fat signal or hyperintensity on diffusion-weighted images did not have prognostic value (all P > 0.05).

CONCLUSIONS

Radiological parameters by CT and MRI may be useful in biological characterization of tumours and prognostification for HCC treated with chemoembolization.

Magnetic resonance imaging of the cirrhotic liver: An update

Noninvasive imaging has become the standard for hepatocellular carcinoma (HCC) diagnosis in cirrhotic livers. In this review paper, we go over the basics of MR imaging in cirrhotic livers and describe the imaging appearance of a spectrum of hepatic nodules marking the progression from regenerative nodules to low- and high-grade dysplastic nodules, and ultimately to HCCs. We detail and illustrate the typical imaging appearances of different types of HCC including focal, multi-focal, massive, diffuse/infiltrative, and intra-hepatic metastases; with emphasis on the diagnostic value of MR in imaging these lesions. We also shed some light on liver imaging reporting and data system, and the role of different magnetic resonance imaging (MRI) contrast agents and future MRI techniques including the use of advanced MR pulse sequences and utilization of hepatocyte-specific MRI contrast agents, and how they might contribute to improving the diagnostic performance of MRI in early stage HCC diagnosis.

Single Hepatocellular Carcinoma: Preoperative MR Imaging to Predict Early Recurrence after Curative Resection

PURPOSE

To identify magnetic resonance (MR) imaging features that enable prediction of early recurrence (<2 years) after curative resection of hepatocellular carcinoma (HCC) and to derive a preoperative prediction model.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board. The requirement to obtain written informed consent was waived. A total of 268 patients who underwent hepatic resection for a single HCC from January 2008 to August 2011 were divided into two cohorts: a training cohort, which was used to derive a prediction model (n = 187), and a validation cohort (n = 81). All MR images from the training cohort were reviewed by two radiologists. A prediction model was constructed by using MR imaging features that were independently associated with early recurrence with use of multiple logistic regression analysis. The performance of the prediction model in the validation cohort was evaluated with respect to discrimination (ie, whether the relative ranking of individual predictions of subsequent early recurrence is in the correct order).

RESULTS

In the training cohort, four MR imaging features were independently associated with early recurrence: rim enhancement (odds ratio [OR] = 3.83; 95% confidence interval [CI]: 1.39, 10.52), peritumoral parenchymal enhancement in the arterial phase (OR = 2.64; 95% CI: 1.27, 5.46), satellite nodule (OR = 4.07; 95% CI: 1.09, 15.21), and tumor size (OR = 1.66; 95% CI: 1.31, 2.09). A prediction model derived from these variables showed an area under the receiver operating characteristic curve (AUC) of 0.788 in the prediction of the risk of early recurrence in the training cohort. When applied to the validation cohort, this model showed good discrimination (AUC, 0.783).

CONCLUSION

The prediction model derived from rim enhancement, peritumoral parenchymal enhancement, satellite nodule, and tumor size can be used preoperatively to estimate the risk of early recurrence after resection of a single HCC.

Current update on combined hepatocellular-cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma is a rare but unique primary hepatic tumor with characteristic histology and tumor biology. Recent development in genetics and molecular biology support the fact that combined hepatocellular-cholangiocarcinoma is closely linked with cholangiocarcinoma, rather than hepatocellular carcinoma.

Combined hepatocellular cholangiocarcinoma tends to present with an more aggressive behavior and a poorer prognosis than either hepatocellular carcinoma or cholangiocarcinoma. An accurate preoperative diagnosis and aggressive treatment planning can play crucial roles in appropriate patient management.

Combined hepatocellular carcinoma-cholangiocarcinoma: report of MR appearance in eleven patients

PURPOSE

To describe the magnetic resonance imaging (MRI) appearance of hepatic combined hepatocellular-cholangiocarcinoma (cHCC-CC) in 11 patients.

MATERIALS AND METHODS

The database of the Department of Pathology was cross-referenced with the MRI database to identify patients with confirmed cHCC-CC who had undergone MRI. Eleven consecutive patients were included (seven female, mean age 57.6 years). All patients were Caucasian. Five of 11 had a clinical history of chronic liver disease. Two radiologists retrospectively analyzed the images in consensus.

RESULTS

cHCC-CC was a single mass in 10/11 patients. Margins were well-defined in 6/11. All tumors showed heterogeneous hyperintensity on T2. On postcontrast imaging, 6/11 showed early ring-enhancement (four noncirrhotic), with progressive enhancement in central portions, and 5/11 patients showed a diffuse heterogeneous early enhancement. Three of these five were cirrhotic and displayed partial washout with portions of contrast retention on later phases. Other findings included: late capsule enhancement (two patients), biliary dilatation (one), venous invasion (three), lymphadenopathy (six), and findings of cirrhosis (five).

CONCLUSION

cHCC-CC presents most commonly as a single mass. Five of 11 had MR findings of cirrhosis. Clues to the diagnosis were moderately high signal on T2, portions of tumor that show progressive enhancement/contrast retention, and frequent lack of capsule. Early enhancement patterns included early ring-enhancement and diffuse heterogeneous enhancement.